volume_mute
If the tube is made longer...
publish date: 2026/05/19 19:27:59.185153 UTC
volume_mute
In a mercury barometer at sea level, what would happen if you replaced the 1-meter tube with a 2-meter tube (both sealed at the top and inverted into the same mercury pool)?
Correct Answer
The mercury would rise to about 76 cm, leaving a longer vacuum at the top
Explanation
The height of the mercury column is determined by atmospheric pressure, not by the length of the tube. At sea level, atmospheric pressure can only support a column of mercury about 76 cm (30 inches) high. A longer tube simply means more empty vacuum space above the mercury column.
Reference
Basic Physics: A Self-Teaching Guide